David Letterman retiring in 2015

NEW YORK — The days are numbered for stupid human tricks and goofy Top 10 lists: David Letterman is preparing to retire from "Late Show" in 2015, in another generational upheaval that will roil the crowded late-night TV schedule.

The host, who turns 67 this month, plans to say good night to his hosting duties once his current contract expires next year. The news, which first leaked via Twitter, was later confirmed by Tom Keaney, a spokesman for Letterman's production company, Worldwide Pants. The move comes mere weeks after the 63-year-old Jay Leno, Letterman's onetime rival, exited NBC's "The Tonight Show" and was replaced by Jimmy Fallon, 39.

Before a "Late Show" audience at the Ed Sullivan Theater in Manhattan, Letterman — a pioneer who reinvented the late-night format in the 1980s with his ironic take on show-business traditions — revealed how he had called CBS Chief Executive Les Moonves to say he would be retiring.

"I just want to reiterate my thanks for the support from the network, all of the people who have worked here, all of the people in the theater, all the people on the staff, everybody at home, thank you very much," Letterman said, ending with a characteristic punch line: "What this means now is that Paul and I can be married." Paul Shaffer, 64, has been Letterman's bandleader since the 1982 premiere of NBC's "Late Night With David Letterman."

Moonves — who sometimes served as the target of Letterman's barbs over the years — also released a statement, calling Letterman's decision "poignant. "There is only one David Letterman. His greatness will always be remembered here, and he will certainly sit among the pantheon of this business," he said.

CBS has not announced a replacement for the host, whose program single-handedly gave the network a late-night presence when it premiered in 1993. Letterman moved to the network after losing a high-profile battle with Leno for the NBC hosting gig at "Tonight."

CBS executives publicly expressed support for Letterman, insisting that the famously guarded host would retire on his own terms and not be edged out like Leno, whom NBC pushed out of the job not once but twice (he returned after Conan O'Brien hosted "Tonight" for seven months). Speculation about Letterman's future at "The Late Show" was briefly quelled late last year when CBS extended his contract to 2015.

Ron Simon, curator of the Paley Center for Media in New York, says that many young viewers today may have little idea how groundbreaking Letterman's humor was 30 years ago, in many ways setting the stage for such contemporary hosts as Fallon, Jimmy Kimmel, Jon Stewart and Stephen Colbert.

Letterman "brought a surreal, almost 'meta' type of comedy to TV, and now he's competing against two viral comedians, the two Jimmys," Simon said. "Beginning with 'SNL' and then Dave, they brought the baby boomer generation to TV."

While Letterman dominated the late-night ratings 20 years ago, his show is more of an also-ran these days. "Late Show" is edged out by Kimmel among young adults — and Fallon has a more than 2-to-1 lead there.

His departure from CBS would seem to signal an end to a 45-year career in broadcast television, starting with local stations in his native Indianapolis. A move to Los Angeles in 1975 led to work as a comedy writer and appearances on variety shows, including one starring Mary Tyler Moore. In 1980, he caught the attention of critics with his short-lived morning program "The David Letterman Show." But Letterman finally found his calling in late-night television, launching "Late Night" on NBC in 1982, where he quickly established himself with signature bits including Stupid Human Tricks and the Top 10 list.

After Carson's retirement in 1992, many, including Letterman, assumed he was the heir apparent for "Tonight," but instead he lost out to Leno in a contentious public battle and decamped to CBS. "The Late Show" premiered in 1993 and at first easily bested Leno's "Tonight Show" in the ratings. While Leno gradually gained the edge in overall viewership, Letterman has enjoyed greater acclaim from critics and his fellow comedians.

After the announcement, it didn't take long for the Twitter love-fest to start. On Thursday afternoon, Jimmy Kimmel tweeted: "David @Letterman is the best there is and ever was."